NPC1 and NPC2 are intracellular transporters that act in tandem to remove cholesterol from the lysosomal compartment37,39,56 and regulate cholesterol homeostasis through the generation of low-density lipoprotein cholesterol-derived oxysterols.56 Loss of function of NPC1 or NPC2 proteins is known to cause the lysosomal storage disease Niemann–Pick disease, type C1 and 2, respectively.37 This evidence concerns the gene NPC2 and Niemann-Pick disease.